ICD-10 mild cognitive disorder: its outcome three years later.

OBJECTIVE

The aims were to (i) report the outcome of mild cognitive disorder (MCD) 3.6 years after initial interview and diagnosis; (ii) identify predictors of new cases of MCD. The hypotheses were that (i) persons with MCD are more likely to develop dementia than those without MCD; (ii) symptoms of anxiety or depression predict MCD caseness at follow-up.

DESIGN

Longitudinal cohort study.

SETTING

Community of elderly people (age 70-97 years).

PARTICIPANTS

612 of 897 elderly subjects (mean 76 years) were reinterviewed. Of the 36 MCD cases originally identified, 25 were available at follow-up. 24 incident cases of MCD were identified.

MAIN OUTCOME MEASURES: ICD-10 dementia, DSM-III-R dementia, ICD-10 mild cognitive disorder diagnoses made by the Canberra Interview for the Elderly, tests of anxiety, depression, neuroticism and cognitive performance.

MAIN

RESULTS

Of the original 25 MCD cases available at follow-up, two had a diagnosis of MCD, and three had a diagnosis of both ICD-10 and DSM-III-R dementia. The prevalence of MCD and DSM-III-R dementia at follow-up was no greater for MCD cases diagnosed at initial interview than in normal subjects at initial interview. There was, however, an increased prevalence of ICD-10 dementia among original MCD cases. At initial interview and at follow-up MCD cases were more anxious and depressed but had similar cognitive performance to normals. For incident cases of MCD the only significant predictor was age.

CONCLUSIONS

MCD cannot be seen to be a specific forerunner of dementia. Those with a diagnosis of MCD are distinguished more by their anxiety, depression and neuroticism than by their cognitive deficits.